Your network contains an Active Directory domain named contoso.com. All servers run Windows Server 2008 R2. All client computers run Windows 7. You discover that users can use Encrypting File System (EFS) when the smart cards on their computers are removed.You need to prevent the users from accessing EFS-encrypted files when their smart cards are removed.From the EFS properties, you click Require a smart card for EFS.What should you do next？（）

• A、Set the Elliptic Curve Cryptography to Allow.
• B、Set the Elliptic Curve Cryptography to Require.
• C、Disable the Allow delegating saved credentials setting.
• D、Disable the Create caching-capable user key from smart card option.